The rapidly growing market for computing devices, e.g. servers, laptop computers, digital cameras, smart phones, and personal digital assistants (PDAs), is an integral facet of modern life. Recently, forms of non-volatile solid-state storage have become feasible and even preferable enabling smaller and more reliable computing devices.
Many non-volatile memory products used today employ an array of flash memory cells formed on one or more integrated circuit chips. As in all integrated circuit applications, there exists continual market pressure to increase the amount of digital data that can be stored in a given area of a silicon substrate, in order to increase the storage capacity of a given size memory card and other types of packages, or to both increase capacity and decrease size and cost per bit.
The responsiveness of flash memory cells typically changes over time as a function of the number of times the cells are erased, re-programmed, and read. This results in the memory cells becoming less reliable as the memory cells age. The result is a limited effective lifetime of the memory cells; where flash memory cells can become unreliable after a number of erasing and re-programming cycles.
In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures adds an even greater urgency to the critical necessity for finding answers to these problems.
Thus, a need remains for data storage systems with longer effective lifetimes and methods for operation. Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.